greenletLightweight in-process concurrent programming.. image:: https://secure.travis-ci.org/python-greenlet/greenlet.png
:target: http://travis-ci.org/python-greenlet/greenlet
The greenlet package is a spin-off of Stackless, a version of CPython
that supports micro-threads called "tasklets". Tasklets run
pseudo-concurrently (typically in a single or a few OS-level threads)
and are synchronized with data exchanges on "channels".
A "greenlet", on the other hand, is a still more primitive notion of
micro-thread with no implicit scheduling; coroutines, in other
words. This is useful when you want to control exactly when your code
runs. You can build custom scheduled micro-threads on top of greenlet;
however, it seems that greenlets are useful on their own as a way to
make advanced control flow structures. For example, we can recreate
generators; the difference with Python's own generators is that our
generators can call nested functions and the nested functions can
yield values too. Additionally, you don't need a "yield" keyword. See
the example in tests/test_generator.py.
Greenlets are provided as a C extension module for the regular
unmodified interpreter.
Greenlets are lightweight coroutines for in-process concurrent
programming.
Who is using Greenlet?
======================
There are several libraries that use Greenlet as a more flexible
alternative to Python's built in coroutine support:
- `Concurrence`_
- `Eventlet`_
- `Gevent`_
.. _Concurrence: http://opensource.hyves.org/concurrence/
.. _Eventlet: http://eventlet.net/
.. _Gevent: http://www.gevent.org/
Getting Greenlet
================
The easiest way to get Greenlet is to install it with pip or
easy_install::
pip install greenlet
easy_install greenlet
Source code archives and windows installers are available on the
python package index at http://pypi.python.org/pypi/greenlet
The source code repository is hosted on github:
https://github.com/python-greenlet/greenlet
The master branch - i.e. the `development version`_ - can be installed
directly by running one of the following::
pip install greenlet==dev
easy_install greenlet==dev
.. _`development version`: https://github.com/python-greenlet/greenlet/zipball/master#egg=greenlet-devRalf Schmitt73fe199050d5c7b459a198b72cfd0d913aeb0c730.4.2